Use LEFT and RIGHT arrow keys to navigate between flashcards;
Use UP and DOWN arrow keys to flip the card;
H to show hint;
A reads text to speech;
24 Cards in this Set
- Front
- Back
- 3rd side (hint)
|
What does the formula (CH²O)n represent? |
The hydrocarbon chain of carbohydrates including sugar, fibre and starch |
Hydrocarbon chain of 3 types of carbohydrates |
|
|
What is a monosaccharide? |
Single sugars (monomers) |
|
|
|
What are isomers? |
Hexosugars where the position of the first carbon is reversed in a beta glucose compared to a alpha glucose |
|
|
|
What types of glucose are isomers? |
Alpha glucose, beta glucose and fructose |
|
|
|
What are disaccharides? |
Double sugars (e.g. maltose is two alpha glucose) |
|
|
|
How are disaccharides formed? |
Two monosaccharides joining in a condensation reaction forming a glycosidic bond |
|
|
|
What does a hydrolysis reaction do? |
Breaks glycosidic bonds and produces water |
|
|
|
What are polysaccharides? |
A large number of monosaccharides bonded forming a polymer |
|
|
|
What is starch? |
A storage of carbohydrates in starch grains in plants containing amylose and amylopectin |
|
|
|
What is amylose? |
A unbranched polymer of alpha glucose bonded by 1-4 glycosidic bonds |
|
|
|
What is amylopectin? |
A slightly branched polymer of alpha glucose bonded by 1-6 glycosidic bonds |
|
|
|
How is a hydrogen bond formed? |
The positive charge of H+ forms a weak bond with the negative charge of O- forming a helix shape |
|
|
|
Why is starch an ideal long-term storage carbohydrate in plants? |
1. Compact due to it's helical shape 2. Insoluble so doesn't effect water potential (osmosis) 3. Slightly branched providing free ends for glucose to be released for respiration (less glucosed released as plants are not as active as animals) 4. Large so can't pass through membrane |
|
|
|
What is glycogen? |
A highly branched storage polysaccharide in muscle cells forming compact granules |
|
|
|
Why is glycogen an ideal long-term storage carbohydrate in animals? |
1. Compact granules 2. Insoluble so doesn't effect water potential (osmosis) 3. Highly branched providing many free ends for rapid glucose release for respiration (rapid glucose release as animals have a high metabolic rate) 4. Large so can't pass through membrane |
|
|
|
What is cellulose? |
A unbranched polymer of beta glucose in which each successive monomer is inverted bringing two OH groups together |
|
|
|
What are microfibrils? |
Bundles of cellulose bonded by many cross-linking hydrogen bonds |
|
|
|
How is a lattice formed? |
Many microfibril bundles forming larger fibrils in a lattice (e.g. plant cell walls) |
|
|
|
Why is cellulose the ideal structural carbohydrate in plants? |
1. Strong due to cross-linking hydrogen bonds to prevent bursting 2. Insoluble so leaves don't dissolve 3. Resistant to hydrolysis so can't be digested |
|
|
|
What is the test for reducing sugars? |
1. Add benedict's reagent, mix and heat2. If orange or brick red test is positive |
|
|
|
What is the test for non-reducing sugars? |
1. Add benedict's reagent, mix and heat 2. If test is negative use a fresh sample to boil with acid then neutralise with alkaline 3. Add benedict's reagent and heat 4. If orange or brick red test is positive |
|
|
|
What is the test for starch? |
1. Add iodine solution 2. If colour changes to dark blue or black test is positive |
|
|
|
What is quantitative result? |
Shows if a test is positive but gives no values |
Valued measurements |
|
|
What is the semi-quantitative assay for reducing sugars? |
1. Final colour of the solution from the test gives a rough idea 2. More sugar will produce more precipitate giving a darker colour |
|
